LLC Converter (Full Bride, Synchronous FETs)


The LLC converter is a resonant converter that can achieve ZVS operation (primary side switch) and ZCS operation (secondary side switch) simultaneously. It achieves low noise and high efficiency by generating a sinusoidal current waveform with the switch network and resonant circuit.
This circuit consists of a full-bridge switch circuit on the primary side and a center-tap transformer on the secondary side using FETs instead of diodes. This type of configuration is commonly used for relatively high power (around several kW).


- Same semiconductor devices
- Series resonance between Cr and Lr
- Lr is sometimes implemented as the leakage inductance of the transformer
- Voltage control is done through frequency high complexity design
- Soft switching is defined by magnetizing inductance Lm, not function of the load.
- Efficiency around 98% suits Titanium!
- Frequency 100..200 kHz



Key Products

Product CategoryProduct familyProduct NumberFeature
Primary Side (HV)600V SJ MOSPrestoMOS (JNx series)excellent switching behaviour (low Qrr, short Trr)
Secondary Side (LV)100V MOSFETRQ3P300BH100V MOSFET in small HSMT8 package
40V MOSFETRS1G300GN40V MOSFET in HSOP8 package
Gate DriverHV sideBM60212FV-CDual driver, ideal for half- and full-bridge topologies.
LV SideBD85506FSynchronous rectification controller IC


Coming soon

Related Topologies

LLC Converter (Full Bridge, Diode Rectification)

Phase-Shifted Full Bridge Converter (Diode Rectification)

Phase-Shifted Full Bridge Converter (Synchronous FETs)